Water filtration the process of water passing through a physical barrier to capture or reduce impurities. This is a simple explanation which could be a very complicated process depending on the type of filter. There are many types of filters that include cartridge, bag, screen, multi-media, ultrafiltration, nanofiltration, and biological filters for example.
Cartridge filters are commonly used to remove suspended matter before another water treatment technology. The filter consists of a housing with a cartridge insert. They are commonly found before a water softener or reverse osmosis systems to remove sand and sediment that could hurt further processes downstream. These are rather small and designed for flow rates of 5-20 GPM. Particulate filters normally range in pore sizes from 200 down to 1 micron. They can be pleated, string, or depth cartridges. The pleated cartridges usually handle higher flow rates and can be rinsed and reused. The latter two can usually remove smaller particulates at a lower flow rate and cannot be reused. Carbon block filters can also fit in these housings and can remove a wide range of chemicals such as chlorine and pesticides. Fillable canisters can also fit inside these same housings and can hold specialized media and resins for tannins, nitrates, arsenic, and lead for example. The 10” or 20” systems are truly too small to be effective for whole house applications unless they are being utilized as particulate filters to protect equipment down stream.
Whole house cartridge filters essentially function the same as the filters mentioned previously. The larger size allows for higher flow rates as the surface area is increased dramatically. Also, with the larger surface area, smaller pore sizes can be used with less frequent maintenance or replacement. More specialized options are available with these filters as the housings are much larger. Applications include high-flow carbon block filters, microfiltration, Lead removal, PFOA (C8) and PFOS removal.
Bag filters are generally used for commercial applications. These are intended for much higher flow rates than the systems above. The most common use if for the removal of suspended matter. However, some of these filters are highly effective at the removal of petroleum at residential flow rates and are more cost effective than the cartridge filters that would address the same issue.
Screen filters can vary greatly in their size and volumes of water it can treat. These are best utilized for the removal of sand and large sediment. The advantage is that one does not need to throw away disposable cartridge filters which can cost money over time. Some screen filters work by water flowing through a screen and gravity dropping particulates to the bottom for a manual purge or automated flush. Others operate by centripetal force and uses a continuous flow of water to purge the sediment.
Disc filters are highly effective and are automated to flush when there is an increase in pressure. These are mostly used in commercial and industrial applications. Amiad is an industry leader and their SK2 unit under the Arkal name can be used for a large residence or irrigation for the effective removal of sediment with near zero maintenance.
Microfilters, ultrafilters, and nanofilters are very specific in their application. Watts Water Technologies developed the HydroSafe biological filter all-in-one filter that can remove chemicals and filter out many common microorganisms. This multibarrier approach also uses an internal UV light to kill any remaining bacteria or viruses that could pass through the filter. Enpress offers the PolyUF which can physically remove the smallest waterborne pathogens and reduce tannins without the use of chemicals that can affect the taste of the water. Nanofilters are mainly used in industrial applications to pretreat water going into a reverse osmosis system.
Backwashing filters (self-cleaning) offer the widest range of water treatment options and these systems can be customized. They can use a single type of media or a blend of two or more medias that can address a wide range of problems such as sediment, chlorine/chemical, iron, manganese, and hydrogen sulfide removal. The valve heads can also be customized to allow for the injection of air or ozone to assist in oxidizing metals and gasses. Accessories, such a flow meters, pressure gauges, test points, and microswitches can be added to aid in quality control, remote access, and activating/deactivating other components downstream.
In some instances, aggressive pretreatment may be required before filtration. For example, well water with iron bacteria or high levels of iron may require a chemical oxidant injection with a holding tank of sufficient contact time to aid in the killing of bacteria and oxidizing metals. Ozone is more effective for high organic and inorganic loads as the contact time and maintenance is greatly reduced. If the pH is low, increasing the pH with a neutralizer may be necessary to effective remove metals present in the water.
There are several type of filtration systems on the market and these are the more common. Intec has relationships with many OEMs and distributors and not all the technologies are discussed appear on this site. Contact Intec today and they will consult with you on the best filtration technology for your application or offer alternative technologies that may better fit your needs.
Air injection and ozone injection are not new to the industry. However, having the injection take place in the valve head to create and gas pocket for advanced oxidation is. It is highly effective and a more reliable injection process without the cost of additional retention tanks or pumps. Air injection is great for the treatment of elevated iron and manganese as well as moderate hydrogen sulfide. EOG (Enhanced Ozone Generator) is effective on high iron, manganese, and elevated hydrogen sulfide levels.
Ozone gas injection, followed with retention and filtration, is used with problematic water. This may include elevated iron, manganese, or hydrogen sulfide or biological concerns. Ozonation is one of the best technologies available to address iron bacteria (sometimes referred to as iron algae). These systems are scalable to your specific need.
Whole house cartridge filters are a cost effective option for addressing many issues. Small 10” and 20” filters are limited in their scope of what contaminants can be removed and even the volume / flow rate they can handle. Large cartridge whole house filters have a greater surface area, provide more contact time that may be necessary to remove contaminants, and can handle higher flow rates with minimal pressure loss.
These filters are ideal for both municipal water and well water. The systems are customized in size and the media used to remove the contaminants of concern. Examples may include, but are not limited to, iron, manganese, hydrogen sulfide, chlorine, chloramines, THMs, fluoride, and pesticides. These systems will backwash on predetermined intervals.